Loaded 1.5+ url behavior. Breaks 1.2 and earlier.
Ignored build/, dist/, django_articles.build-info/
Quoted literal url args for future compatibility
Used "in" instead of "has_key"
Fix for alternate storage back-ends.

This change replaces attachment.path with uploadedfile.url for
compatibility with django-storage.

Testing done (django 1.4):
- Before the change, I was getting a NotImplementedError exception of
  "This backend doesn't support absolute paths."
- After the change, I'm able to upload attachments to AWS as well as a
  local file system.